Air-separator for cement-grinding mills.



No. 778.452. PATBNTED DEC. 27, 1904.

H. HTZEL.

AlR SEPARATOR. FOR CEMENT GRINDNG MLLS.

APPLICATION FILED APR-.5,1904.

ZSHEETS-SEET 1.

PATBNTED DEC. 27, 1904.

H. HITZBL.

PARATOR FOR C EMENT GRINDNG MILLS.

APPLICATION HLM) APR. 5, 1004.

AIR 43E UNTTED STATES Patented December 2'7, 1904.

PATENT OEEICE.

HARRY HITZEL, OE ALPHA, NEV JERSEY, ASSIGNOR, BY MESNE ASSIGN- MENTS, TO LEHIGH PULVERIZER MILL COMPANY, OF OATASAUQUA, PENNSYLVANIA, A CORPORATION OF PENNSYLVANIA.

ABR-SEPARATOR FOR CEMENT-@FUNDING IVIILLS..

SPECIFICATION forming part of Letters Patent No. 778,452, dated December` 27', 1904.

Application led April 5, 1904. Serial No. 201,655.

To @ZZ rub/mit it nul/y concern:

Be it known that I, HARRY HrTzEL, a citizen of the United States, residing' at Alpha,-in the county of lVarren and State of New Jersey,

5 have invented certain new and useful Improvements in Air-Separators for Cement-Grrind ing Mills, of which the following' is a specification.

My invention has relation to a cement-grind- Io ing mill of the type wherein the materials are ground by balls or rolls passing over the surface of an annulus or ring; and in such connection it relates to an improved means for separating the iinely-divided or pulver-ized 1. 5 materials and conveying the same away from the grinding mechanism, as well as to the construction and arrangement of parts of such a machine,substantially as hereinafter described and claimed.

2o The principal objects of my invention are, iirst, to utilize efficiently, economically, and simply an airexhaust to withdraw the Aline cement particles from the grinding-path and to pass the same into a separating' or settling chamber; second, to provide means whereby the cement-laden air lifted by the air-exhaust may be discharged at varying angles against a partition in the settling-chamber to vary the degree of lineness of the particles entering said chamber, and, third, to utilize the air-eX- haust not only as a separating means` but also to sct up in the grinding-path induced air-currents to properly season the cement in the grinding operation.

3 5 The nature and scope of my invention will- Referring to the drawings, a represents the driving-shaft, preferably arranged vertically, and a the driving-pulley for the shaft. Within a casing b, traversed by the shaft a, is arranged the annulus or grinding-ring d. Ar-` ranged to rotate with the shaft a are respectively the exhaust-fan e, the frame or carrier f for the grinding-balls f, and the disk-like platform g, upon which the fine particles from the mill are collected after separation and prior to their discharge through the spout or outlet g. The casing 7) is supported by a framework 7)', resting upon a bed-plate b2 of the 60 mill, and the casingJ) supports on its exterior an annular chamber L, which, as hereinafter described, is the settling-chamber, into which the materials of requisite tineness pass. The exhaust-fan e is of ordinary construction in that its body e', from which the fan-blades radiate, is hollow or concave, and this hollow body e is utilized in the present invention as a hopper or receptacle for the unground materials, a chute or inlet-opening e2 conducting the 70 materials from the exterior of the mill to the hollow body e. The annular settling-chamber /t has the base of its innermost wall open, as-at 7b', directly opposite the fan e, and this opening /L/ is screened or guarded by supcrposed plates 7a2, arranged as illustrated in Fig. 2 and grouped in polygonal form around the fan e. These plates lf, as clearly shown in Fig. 3, are hinged at one edge to fixed portions of the easing b and are free to drop at the other edge. 8O A stem 713 passes through each plate in series and carries pins 71,4, which serve as supports for the plates 7a2. An adjusting-nut LS serves to raise or lower the stern h3, and thereby opens or closes the space between adjacent plates 7b2, as wellas alters the angular position of the plates, substantially as in the case of a Venetian blind or register. It follows that the adjustment of the stems h3 will serve to increase or decrease the inlet-opening It into the settling-chamber /L and to vary the angle of said plates, and thus the exhaust created by the fan e can be augmented or decreased to compensate for higher or lower speeds of said fan e, as well as regulate the fneness of the cement particles to be exhausted, and the direction ot' the exit of the cement-laden air may be varied. From the hollow body c pipes or tubes tf extend below the base oit the fan-blades to convey the materials to the balls or rolls f. The materials are ground between the balls f and the annulus (I, and the exhaust-fan e,

arranged directly above the grinding-path, elevates the liner particles therefrom and discharges the same through the damper-plates It into the chamber t. Air-inlet portsm conduct air from the exterior of the mill into the casing below the fan @and above the grindingpath, and hence a constant circulation ot' air within the casing Z) is maintained above the grinding-path by the suction action of the fan e and the expansion of the air in the casing as it enters through the ports m. This circulation sets up induced currents of air around the balls f and annulus (l, and the annulus and balls are cooled by said currents. The induced currents also traverse the ground materials and properly season the same before they enter the settling-chamber t. The top of the chamber /t is covered with netting, bolting-cloth, or other suitable equivalent means /zf to permit of the escape and expansion of the air, but not of the particles of cement with which the air is laden, as it enters thc chamber L. The chamber /t has also an internal partition la", acting as a battle-plate to break the force of the cement-laden air passing through the deilector-plates 7b2. By reason of this screened upper end /t to the chamber /t and the partition L the particles ot' tine cement enter the main body of the chamber It in a relatively quiescent state, so as to respond to the influence of gravity, and pass downward therein to the annular outlet-passage w, formed in the walls of the casing' 7). The passage/a discharges upon the disk-like deliveryplatform g, which as it revolves drops the line cement into the outlet or spout 0. rlhe partitions t serve also to return the coarserground particles through the passage-way It? at the base of the partition 7L to the interior of the casing Z2 and to the balls f. By guarding the inlet to the settling-chamber /t with the deiector-plates it, as described, and arranging' said chamber /t and plates so that the cementA particles may be directed with more or less angularity upon the partition it, as indicated in full and dotted lines in Fig. 3, the air enters the main body of the chamber t with little or no force and is discharged under the influence of gravity therefrom, and the use of bolting-cloth is obviated. Asis well known, such constructions as of necessity depend upon boltng-cloth to regulate the lineness of the cement particles escaping from the` mill and upon an air-blast to force the particles through the cloth are defective in that the bolting-cloth is speedily perforated by coarser particles of cement forced therethrough by the blast, and the leakage through the cloth thus occasioned results in the passage ot' mixed materials, which require rebolting and reseparation before the product can pass the tests required.

The particular construction and arrangement of parts described and illustrated may be varied without departing from the spirit or' my invention.

Having thus described the nature and 0bjects of my invention, what I claim as new, and desire to secure by Letters Patent, is-- 1. In a cement-grinding mill, a casing having peripheral outlets, a grinding mechanism located within the casing below the outlets, a settling-chamber located outside the casing and surrounding said outlets, an air-exhausting apparatus located Within the casing adjacent to the outlets and above the grindingpath and means for controlling the outlets from the casing.

2. In a cement-grinding mill, a casing having peripheral outlets, an air-exhausting apparatus arranged Within the casing above the grinding-path and adjacent to the outlets, a settling-chamber surrounding said outlets, an inlet for air from the exterior of the casing, arranged below the outlets from the casing and above the grinding-path and means for controlling the outlets from the casing.

3. In a cement-grinding mill, a casing having` peripheral outlets, a grinding mechanism arranged in the casing below said outlets, an air-exhausting apparatus arranged within the casing adjacent to the outlets and above the grinding-path, a settling-chamber surrounding the outlets from the casing and adjustable means for controlling the outlets from the casing.

et. In a cement-grinding mill, acasing having peripheral outlets, a grinding mechanism located within the casing' below said outlets, an air-exhausting apparatus located within the casing above the grinding-path and-adjacent to the outlets, a settling-chamber surrounding said outlets, a series of superposed detlectorplates guarding each outlet` and means for moving said detlector-plates in the casing to vary the angle or' discharge through said outlets.

5. In a cement-grinding'mill, a settlingchamber arranged at the top of the mill and outside of the mill proper, an air-exhaust apparatus located within the mill above the grinding-path and arranged to discharge cement-laden air into the settling-chamber, an air-inlet located below the exhaust apparatus and above the grinding-path, a partition within the settling-chamber against which the air from the inlets is discharged by said exhaust apparatus, and a cover of fine netting for the top of said settling-chamber.

6. In acement-grinding mill, an air-exhaust IOO apparatus arranged Within the mill above the In testimony whereof I havev hereunto set grinding-path, means lor introducing eXtermy signature 1n the presence of two subscrib- IO nal air into the mill below the air-exhaust aping Witnesses.

paratus, a grinding` mechanism arranged loe- 5 low the air-introducingmeans, and a Settling- HARRY HITZEL' chamber located outside the mill propel' and Vitnesses: having a screened top through which the air W. H. WALTERS,

from the exhaust apparatus is discharged. A. F. GERSTELL. 

